BACKGROUND A patient with type Ⅲ Kummell’s disease had a ruptured posterior cortex of the fractured vertebral body, which caused spinal cord compression. An open surgery was considered the best choice of operation. ...BACKGROUND A patient with type Ⅲ Kummell’s disease had a ruptured posterior cortex of the fractured vertebral body, which caused spinal cord compression. An open surgery was considered the best choice of operation. However, the patient and her family refused open surgery and instead demanded a minimally invasive surgical treatment such as percutaneous vertebroplasty(PVP). After preoperative discussion, we finally adopted the novel therapy of traditional Chinese medicine manipulative reduction(TCMMR) combined with PVP.CASE SUMMARY A patient with type Ⅲ Kummell’s disease exhibiting bone block-induced spinal cord compression was admitted to our hospital. She suffered from a variety of medical disorders but refused open surgery, and instead asked for PVP surgery. TCMMR, in parallel with PVP, was used to restore the height of the compressed vertebral body and reduce the symptoms of spinal cord compression by the bone block in order to strengthen the vertebral body and prevent further collapse. The surgery was very successful. The height of the compressed vertebra was restored, and the symptom of spinal cord compression by bone block was reduced successfully via TCMMR. The fractured vertebra was solidified by the PVP. The pain visual analog score declined from preoperative 7 scores to postoperative 2 scores, and the Frankel spinal cord scale increased from preoperative D degree to postoperative E degree.CONCLUSION The new method has advantages in treating patients with type Ⅲ Kummell’s disease who cannot be treated with open surgery.展开更多
Ninety-four patients with lumbar intervertebral disc herniation were enrolled in this study. Of these, 48 were treated with Feng's Spinal Manipulation, hot fomentation, and bed rest (treatment group). The remaining...Ninety-four patients with lumbar intervertebral disc herniation were enrolled in this study. Of these, 48 were treated with Feng's Spinal Manipulation, hot fomentation, and bed rest (treatment group). The remaining 46 patients were treated with hot fomentation and bed rest only (control group). After 3 weeks of treatment, clinical parameters including the angle of straight-leg raising, visual analogue scale pain score, and Japanese Orthopaedic Association score for low back pain were improved. The treatment group had significantly better improvement in scores than the control group. Magnetic resonance myelography three-dimensional reconstruction imaging of the vertebral canal demonstrated that filling of the compressed nerve root sleeve with cerebrospinal fluid increased significantly in the treatment group. The diameter of the nerve root sleeve was significantly larger in the treatment group than in the control group. However, the sagittal diameter index of the herniated nucleus pulposus and the angle between the nerve root sleeve and the thecal sac did not change significantly in either the treatment or control groups. The effectiveness of Feng's Spinal Manipulation for the treatment of symptoms associated with lumbar intervertebral disc herniation may be attributable to the relief of nerve root compression, without affecting the herniated nucleus pulposus or changing the morphology or position of the nerve root.展开更多
We present a design of an acoustic levitator consisting of three pairs of opposite transducer arrays.Three orthogonal standing waves create a large number of acoustic traps at which the particles are levitated in mid-...We present a design of an acoustic levitator consisting of three pairs of opposite transducer arrays.Three orthogonal standing waves create a large number of acoustic traps at which the particles are levitated in mid-air.By changing the phase difference of transducer arrays,three-dimensional manipulation of particles is successfully realized.Moreover,the relationship between the translation of particles and the phase difference is experimentally investigated,and the result is in agreement with the theoretical calculation.This design can expand the application of acoustic levitation in many fields,such as biomedicine,ultrasonic motor and new materials processing.展开更多
The electrocatalytic carbon dioxide reduction reaction(CO_(2) RR)producing HCOOH and CO is one of the most promising approaches for storing renewable electricity as chemical energy in fuels.SnO_(2) is a good catalyst ...The electrocatalytic carbon dioxide reduction reaction(CO_(2) RR)producing HCOOH and CO is one of the most promising approaches for storing renewable electricity as chemical energy in fuels.SnO_(2) is a good catalyst for CO_(2)-to-HCOOH or CO_(2)-to-CO conversion,with different crystal planes participating the catalytic process.Among them,(110)surface SnO_(2) is very stable and easy to synthesisze.By changing the ratio of Sn:O for SnO_(2)(110),we have two typical SnO_(2) thin films:fully oxidized(stoichiometric)and partially reduced.In this work,we are concerned with different metals(Fe,Co,Ni,Cu,Ru,Rh,Pd,Ag,Os,Ir,Pt,and Au)-doped SnO_(2)(110)with different activity and selectivity for CO_(2) RR.All these changes are manipulated by adjusting the ratio of Sn:O in(110)surface.The results show that stochiometric and reduced Cu/Ag doped SnO_(2)(110)have different selectivity for CO_(2) RR.More specifically,stochiometric Cu/Ag-doped SnO_(2)(110)tends to generate CO(g).Meanwhile,the reduced surface tends to generate HCOOH(g).Moreover,we also considered the competitive hydrogen evolution reaction(HER).The catalysts SnO_(2)(110)doped by Ru,Rh,Pd,Os,Ir,and Pt have high activity for HER,and others are good catalysts for CO_(2) RR.展开更多
One of the main obstacles limiting the performance of protonic ceramic fuel cells(PCFCs) is the sluggish kinetics of the oxygen reduction reaction(ORR) at reduced temperatures.Here,the surface manipulation of a triple...One of the main obstacles limiting the performance of protonic ceramic fuel cells(PCFCs) is the sluggish kinetics of the oxygen reduction reaction(ORR) at reduced temperatures.Here,the surface manipulation of a triple-conducting cathode BaCe_(0.5)Pr_(0.3)Y_(0.2)O_(3-δ)(BCPY) by an efficient catalyst coating PrNi_(0.5)Co_(0.5)O_(3-δ)(PNC) to enhance the ORR activity and CO_(2) tolerance is reported.The developed PNC-coated BCPY cathode achieves the polarization resistance of 0.25 and 1.00 Ω cm^(2) at 600 and 500 ℃,respectively,approximately 1/5 of that for the pristine BCPY cathode(0.99 and 4.79 Ω cm^(2)),while maintaining an excellent CO_(2) tolerance.The single cell on a BaZr_(0.8)Yb_(0.2)O_(3-δ) electrolyte also exhibits a high peak power density of 0.79 W cm^(-2)at 700 ℃ and a stable operation for 200 h at 600 ℃.Such high ORR activity is mainly attributed to the synergistic effect of BCPY support and PNC nanoparticles.Namely,BCPY provides a tripleconducting path(mainly protons),and PNC nanoparticles facilitates surface oxygen exchange and steam adsorption/desorption processes due to the enriched surface oxygen vacancies.This study will provide a new design strategy for developing high-performance PCFCs cathode.展开更多
The failure mechanism of two-dimensional(2D) and three-dimensional(3D) slopes were investigated by using the strength reduction method.An extensive study of 3D effect was conducted with respect to boundary conditi...The failure mechanism of two-dimensional(2D) and three-dimensional(3D) slopes were investigated by using the strength reduction method.An extensive study of 3D effect was conducted with respect to boundary conditions,shear strength and concentrated surcharge load.The results obtained by 2D and 3D analyses were compared and the applicable scope of 2D and 3D method was analyzed.The results of the numerical simulation show that 3D effect is sensitive to the width of slip surface.As for slopes with specific geometry,3D effect is influenced by dimensionless parameter c/(γHtanφ).For those infinite slopes with local loading,external load has the major impact on failure mode.For those slopes with local loading and geometric constraints,the failure mode is influenced by both factors.With the increase of loading length,boundary condition exerts a more significant impact on the failure mode,and then 2D and 3D stability charts are developed,which provides a rapid and reliable way to calculate 2D and 3D factor of safety without iteration.Finally,a simple and practical calculation procedure based on the study of 3D effect and stability charts is proposed to recognize the right time to apply 2D or 3D method.展开更多
Optimizing the sensor energy is one of the most important concern in Three-Dimensional(3D)Wireless Sensor Networks(WSNs).An improved dynamic hierarchical clustering has been used in previous works that computes optimu...Optimizing the sensor energy is one of the most important concern in Three-Dimensional(3D)Wireless Sensor Networks(WSNs).An improved dynamic hierarchical clustering has been used in previous works that computes optimum clusters count and thus,the total consumption of energy is optimal.However,the computational complexity will be increased due to data dimension,and this leads to increase in delay in network data transmission and reception.For solving the above-mentioned issues,an efficient dimensionality reduction model based on Incremental Linear Discriminant Analysis(ILDA)is proposed for 3D hierarchical clustering WSNs.The major objective of the proposed work is to design an efficient dimensionality reduction and energy efficient clustering algorithm in 3D hierarchical clustering WSNs.This ILDA approach consists of four major steps such as data dimension reduction,distance similarity index introduction,double cluster head technique and node dormancy approach.This protocol differs from normal hierarchical routing protocols in formulating the Cluster Head(CH)selection technique.According to node’s position and residual energy,optimal cluster-head function is generated,and every CH is elected by this formulation.For a 3D spherical structure,under the same network condition,the performance of the proposed ILDA with Improved Dynamic Hierarchical Clustering(IDHC)is compared with Distributed Energy-Efficient Clustering(DEEC),Hybrid Energy Efficient Distributed(HEED)and Stable Election Protocol(SEP)techniques.It is observed that the proposed ILDA based IDHC approach provides better results with respect to Throughput,network residual energy,network lifetime and first node death round.展开更多
The strategy of combining highly conductive frameworks with abundant active sites is desirable in the preparation of alternative catalysts to commercial Pt/C for the oxygen reduction reaction (ORR). In this study, N...The strategy of combining highly conductive frameworks with abundant active sites is desirable in the preparation of alternative catalysts to commercial Pt/C for the oxygen reduction reaction (ORR). In this study, N-doped graphene (NG) and carbon nanotubes (CNT) were grown in-situ on Co-containing carbon nanofibers (CNF) to form three-dimensional (3D) interconnected networks. The NG and CNT bound the interlaced CNF together, facilitating electron transfer and providing additional active sites. The 3D interconnected fiber networks exhibited excellent ORR catalytic behavior with an onset potential of 0.924 V (vs. reversible hydrogen electrode) and a higher current density than Pt/C beyond 0.720 V. In addition, the hybrid system exhibited superior stability and methanol tolerance to Pt/C in alkaline media. This method can be extended to the design of other 3D interconnected network architectures for energy storage and conversion applications.展开更多
Background: The treatment of high-grade developmental spondylolisthesis (HGDS) is still challenging and controversial. In this study, we investigated the efficacy of the posterior reduction and monosegmental fusion...Background: The treatment of high-grade developmental spondylolisthesis (HGDS) is still challenging and controversial. In this study, we investigated the efficacy of the posterior reduction and monosegmental fusion assisted by intraoperative three-dimensional (3D) navigation system in managing the HGDS. Methods: Thirteen consecutive HGDS patients were treated with posterior decompression, reduction and monosegmental fusion ofL5/S1, assisted by intraoperative 3D navigation system. The clinical and radiographic outcomes were evaluated, with a minimum follow-up of 2 years. The differences between the pre- and post-operative measures were statistically analyzed using a two-tailed, paired t-test. Results: At most recent follow-up, 12 patients were pain-free. Only l patient had moderate pain, There were no permanent neurological complications or pseudarthrosis. The magnetic resonance imaging showed that there was no obvious disc degeneration in the adjacent segment. All radiographic parameters were improved. Mean slippage improved from 63.2% before surgery to 12.2% after surgery and 11.0% at latest follow-up. Lumbar lordosis changed from preoperative 34.9 ± 13.3° to postoperative 50.4 ±9.9°, and 49.3 ± 7.8° at last follow-up. L5 incidence improved from 71.0 ± 11.3° to 54.0 ± 1 1.9° and did not change significantly at the last follow-up 53.±1 15.4°. While pelvic incidence remained unchanged, sacral slip significantly decreased from preoperative 32.7± 12.5° to postoperative 42.6 ± 9.8°and remained constant to the last follow-up 44.4 ± 6.9°. Pelvic tilt significantly decreased from 38.4±12.5° to 30.9± 8.1° and remained unchanged at the last fbllow-up 28.1± 11.2°. Conclusions: Posterior reduction and monosegmental fusion of L5/S1 assisted by intraoperative 3D navigation are an effective technique for managing high-grade dysplastic spondylolisthesis. A complete reduction of local deformity and excellent correction of overall sagittal balance can be achieved.展开更多
Purpose:This meta-analysis compared the clinical outcome of three-dimensional(3D)printing combined with open reduction and internal fixation(ORIF)to traditional ORIF in the treatment of acetabular fractures.Methods:We...Purpose:This meta-analysis compared the clinical outcome of three-dimensional(3D)printing combined with open reduction and internal fixation(ORIF)to traditional ORIF in the treatment of acetabular fractures.Methods:We searched the Cochrane Library,PubMed,Embase,VIP database,CNKI,and Wanfang data-base with keywords"acetabular fracture","3D printing","three-dimensional printing","open reduction and internal fixation","Acetabulum","Acetabula"from January 2000 to March 2020.Two reviewers independently selected articles,extracted data,assessed the quality evidence and risk bias of included trials using the Cochrane Collaboration’s tools and/or Newcastle-Ottawa scale.When the two analysts had different opinions,they would ask the third analyst for opinion.Randomized controlled trials or retrospective comparative studies of 3D printing combined with ORIF(3D printing group)versus traditional ORIF(conventional group)in the treatment of acetabular fractures were selected.The data of operation time,intraoperative blood loss,intraoperative fluoroscopy times,incidence of complications,excellent and good rate of Matta score for reduction,and excellent and good rate of hip function score were extracted.Stata14.0 statistical software was used for data analysis.Results:Altogether 9 articles were selected,including 5 randomized controlled trials and 4 retrospective studies.A total of 467 patients were analyzed,250 in the conventional group,and 217 in the 3D printing group.The operation time in the 3D printing group was less than that in the conventional group and the difference was statistically significant(standardized mean difference(SMD)=-1.19,95%CI:-1.55 to-0.82,p<0.05).The intraoperative bleeding volume of the 3D printing group was significantly lower than that of the conventional group(SMD=-1.08,95%CI:-1.65 to-0.51,p<0.05).The fluoroscopy times were less in the 3D printing group than in the conventional group and the difference was statistically significant(SMD=-1.64,95%CI:-2.35 to-0.93,p<0.05).The total incidence of complications in the 3D printing group was significantly lower than that in the conventional group(OR=0.43,95%CI:0.24-0.79,p<0.05).There was no significant difference in the excellent and good rate of Matta score for reduction between the two groups(OR=0.60,95%CI:0.34-1.06,p>0.05).There was no significant difference in the excellent and good rate of hip function score at the end of postoperative follow-up between the two groups(OR=0.84,95%CI:0.46-1.56,p>0.05),but the follow-up time varies from 6 months to 40 months.Conclusion:Compared with traditional ORIF,3D printing combined with ORIF has certain advantages in terms that 3D printing not only helps surgeons to understand acetabular fractures more intuitively,but also effectively reduces operation time,intraoperative blood loss,intraoperative fluoroscopy times,and postoperative complications.However,there were no significant differences in the excellent and good rate of Matta score for reduction and the excellent and good rate of hip function score at the end of follow-up.展开更多
Holograms provide a characteristic manner to display and convey information, and have been improved to provide better user interactions Holographic interactions are important as they improve user interactions with vir...Holograms provide a characteristic manner to display and convey information, and have been improved to provide better user interactions Holographic interactions are important as they improve user interactions with virtual objects. Gesture interaction is a recent research topic, as it allows users to use their bare hands to directly interact with the hologram. However, it remains unclear whether real hand gestures are well suited for hologram applications. Therefore, we discuss the development process and implementation of three-dimensional object manipulation using natural hand gestures in a hologram. We describe the design and development process for hologram applications and its integration with real hand gesture interactions as initial findings. Experimental results from Nasa TLX form are discussed. Based on the findings, we actualize the user interactions in the hologram.展开更多
目的:通过Meta分析,比较手法复位联合咬合板治疗颞下颌关节盘不可复性前移位患者疼痛与最大张口度疗效是否优于仅进行手法或仅进行咬合板治疗。方法:计算机检索Web of Science、PubMed、Cochrane Library、维普(VIP)、中国知网(CNKI)、...目的:通过Meta分析,比较手法复位联合咬合板治疗颞下颌关节盘不可复性前移位患者疼痛与最大张口度疗效是否优于仅进行手法或仅进行咬合板治疗。方法:计算机检索Web of Science、PubMed、Cochrane Library、维普(VIP)、中国知网(CNKI)、万方中手法复位联合咬合板治疗颞下颌关节盘不可复性前移位的随机对照试验(RCTs)文献,并参考Cochrane手册评估文献质量,运用RevMan5.4软件分析结局指标。结果:本研究纳入6个RCTs,患者共计393例。Meta分析结果显示,对于颞下颌关节盘不可复性前移位患者,观察组进行手法复位联合咬合板治疗,在降低疼痛评分[SMD=-0.34,95%CI(-0.54,-0.13),P=0.001]与改善最大张口度[SMD=0.51,95%CI(0.31,0.71),P<0.00001]方面疗效均比对照组较优,差异具有统计学意义(P<0.05)。结论:手法复位联合咬合板治疗改善颞下颌关节盘不可复性前移位患者疼痛和最大张口度疗效优于单独使用手法复位或单独佩戴咬合板。展开更多
文摘BACKGROUND A patient with type Ⅲ Kummell’s disease had a ruptured posterior cortex of the fractured vertebral body, which caused spinal cord compression. An open surgery was considered the best choice of operation. However, the patient and her family refused open surgery and instead demanded a minimally invasive surgical treatment such as percutaneous vertebroplasty(PVP). After preoperative discussion, we finally adopted the novel therapy of traditional Chinese medicine manipulative reduction(TCMMR) combined with PVP.CASE SUMMARY A patient with type Ⅲ Kummell’s disease exhibiting bone block-induced spinal cord compression was admitted to our hospital. She suffered from a variety of medical disorders but refused open surgery, and instead asked for PVP surgery. TCMMR, in parallel with PVP, was used to restore the height of the compressed vertebral body and reduce the symptoms of spinal cord compression by the bone block in order to strengthen the vertebral body and prevent further collapse. The surgery was very successful. The height of the compressed vertebra was restored, and the symptom of spinal cord compression by bone block was reduced successfully via TCMMR. The fractured vertebra was solidified by the PVP. The pain visual analog score declined from preoperative 7 scores to postoperative 2 scores, and the Frankel spinal cord scale increased from preoperative D degree to postoperative E degree.CONCLUSION The new method has advantages in treating patients with type Ⅲ Kummell’s disease who cannot be treated with open surgery.
基金supported by grants from the Key Topics of China Traditional Chinese Medicine Scientific Research Project,General Logistics Department of Chinese PLA,No.10ZYZ125the Army Medical Science and Technology the125Scientific Research Projects,Chinese PLA,No.AKJ11J004
文摘Ninety-four patients with lumbar intervertebral disc herniation were enrolled in this study. Of these, 48 were treated with Feng's Spinal Manipulation, hot fomentation, and bed rest (treatment group). The remaining 46 patients were treated with hot fomentation and bed rest only (control group). After 3 weeks of treatment, clinical parameters including the angle of straight-leg raising, visual analogue scale pain score, and Japanese Orthopaedic Association score for low back pain were improved. The treatment group had significantly better improvement in scores than the control group. Magnetic resonance myelography three-dimensional reconstruction imaging of the vertebral canal demonstrated that filling of the compressed nerve root sleeve with cerebrospinal fluid increased significantly in the treatment group. The diameter of the nerve root sleeve was significantly larger in the treatment group than in the control group. However, the sagittal diameter index of the herniated nucleus pulposus and the angle between the nerve root sleeve and the thecal sac did not change significantly in either the treatment or control groups. The effectiveness of Feng's Spinal Manipulation for the treatment of symptoms associated with lumbar intervertebral disc herniation may be attributable to the relief of nerve root compression, without affecting the herniated nucleus pulposus or changing the morphology or position of the nerve root.
基金Supported by the Beijing College Students’Innovation and Entrepreneurship Training Program under Grant No BJ17040
文摘We present a design of an acoustic levitator consisting of three pairs of opposite transducer arrays.Three orthogonal standing waves create a large number of acoustic traps at which the particles are levitated in mid-air.By changing the phase difference of transducer arrays,three-dimensional manipulation of particles is successfully realized.Moreover,the relationship between the translation of particles and the phase difference is experimentally investigated,and the result is in agreement with the theoretical calculation.This design can expand the application of acoustic levitation in many fields,such as biomedicine,ultrasonic motor and new materials processing.
基金supported by the Ministry of Science and Technology(No.2017YFA0204904,No.2016YFA0400900,and No.2016YFA0200600)the National Natural Science Foundation of China(No.21973086 and No.21633006)。
文摘The electrocatalytic carbon dioxide reduction reaction(CO_(2) RR)producing HCOOH and CO is one of the most promising approaches for storing renewable electricity as chemical energy in fuels.SnO_(2) is a good catalyst for CO_(2)-to-HCOOH or CO_(2)-to-CO conversion,with different crystal planes participating the catalytic process.Among them,(110)surface SnO_(2) is very stable and easy to synthesisze.By changing the ratio of Sn:O for SnO_(2)(110),we have two typical SnO_(2) thin films:fully oxidized(stoichiometric)and partially reduced.In this work,we are concerned with different metals(Fe,Co,Ni,Cu,Ru,Rh,Pd,Ag,Os,Ir,Pt,and Au)-doped SnO_(2)(110)with different activity and selectivity for CO_(2) RR.All these changes are manipulated by adjusting the ratio of Sn:O in(110)surface.The results show that stochiometric and reduced Cu/Ag doped SnO_(2)(110)have different selectivity for CO_(2) RR.More specifically,stochiometric Cu/Ag-doped SnO_(2)(110)tends to generate CO(g).Meanwhile,the reduced surface tends to generate HCOOH(g).Moreover,we also considered the competitive hydrogen evolution reaction(HER).The catalysts SnO_(2)(110)doped by Ru,Rh,Pd,Os,Ir,and Pt have high activity for HER,and others are good catalysts for CO_(2) RR.
基金partially based on results obtained from projects, Development of Ultra-High Efficiency Protonic Ceramic Fuel Cell Devices, WP1 Development of Innovative High-Performance Electrodes, JPNP20003, commissioned by the New Energy and Industrial Technology Development Organization (NEDO)supported by Grant-in-Aid for Japan Society for the Promotion of Science (JSPS) Postdoctoral Fellowships for Research in Japan (JP21F20736)。
文摘One of the main obstacles limiting the performance of protonic ceramic fuel cells(PCFCs) is the sluggish kinetics of the oxygen reduction reaction(ORR) at reduced temperatures.Here,the surface manipulation of a triple-conducting cathode BaCe_(0.5)Pr_(0.3)Y_(0.2)O_(3-δ)(BCPY) by an efficient catalyst coating PrNi_(0.5)Co_(0.5)O_(3-δ)(PNC) to enhance the ORR activity and CO_(2) tolerance is reported.The developed PNC-coated BCPY cathode achieves the polarization resistance of 0.25 and 1.00 Ω cm^(2) at 600 and 500 ℃,respectively,approximately 1/5 of that for the pristine BCPY cathode(0.99 and 4.79 Ω cm^(2)),while maintaining an excellent CO_(2) tolerance.The single cell on a BaZr_(0.8)Yb_(0.2)O_(3-δ) electrolyte also exhibits a high peak power density of 0.79 W cm^(-2)at 700 ℃ and a stable operation for 200 h at 600 ℃.Such high ORR activity is mainly attributed to the synergistic effect of BCPY support and PNC nanoparticles.Namely,BCPY provides a tripleconducting path(mainly protons),and PNC nanoparticles facilitates surface oxygen exchange and steam adsorption/desorption processes due to the enriched surface oxygen vacancies.This study will provide a new design strategy for developing high-performance PCFCs cathode.
基金Project (10972238) supported by the National Natural Science Foundation of ChinaProject (2010ssxt237) supported by the Excellent Doctoral Thesis Program of Central South University,China
文摘The failure mechanism of two-dimensional(2D) and three-dimensional(3D) slopes were investigated by using the strength reduction method.An extensive study of 3D effect was conducted with respect to boundary conditions,shear strength and concentrated surcharge load.The results obtained by 2D and 3D analyses were compared and the applicable scope of 2D and 3D method was analyzed.The results of the numerical simulation show that 3D effect is sensitive to the width of slip surface.As for slopes with specific geometry,3D effect is influenced by dimensionless parameter c/(γHtanφ).For those infinite slopes with local loading,external load has the major impact on failure mode.For those slopes with local loading and geometric constraints,the failure mode is influenced by both factors.With the increase of loading length,boundary condition exerts a more significant impact on the failure mode,and then 2D and 3D stability charts are developed,which provides a rapid and reliable way to calculate 2D and 3D factor of safety without iteration.Finally,a simple and practical calculation procedure based on the study of 3D effect and stability charts is proposed to recognize the right time to apply 2D or 3D method.
文摘Optimizing the sensor energy is one of the most important concern in Three-Dimensional(3D)Wireless Sensor Networks(WSNs).An improved dynamic hierarchical clustering has been used in previous works that computes optimum clusters count and thus,the total consumption of energy is optimal.However,the computational complexity will be increased due to data dimension,and this leads to increase in delay in network data transmission and reception.For solving the above-mentioned issues,an efficient dimensionality reduction model based on Incremental Linear Discriminant Analysis(ILDA)is proposed for 3D hierarchical clustering WSNs.The major objective of the proposed work is to design an efficient dimensionality reduction and energy efficient clustering algorithm in 3D hierarchical clustering WSNs.This ILDA approach consists of four major steps such as data dimension reduction,distance similarity index introduction,double cluster head technique and node dormancy approach.This protocol differs from normal hierarchical routing protocols in formulating the Cluster Head(CH)selection technique.According to node’s position and residual energy,optimal cluster-head function is generated,and every CH is elected by this formulation.For a 3D spherical structure,under the same network condition,the performance of the proposed ILDA with Improved Dynamic Hierarchical Clustering(IDHC)is compared with Distributed Energy-Efficient Clustering(DEEC),Hybrid Energy Efficient Distributed(HEED)and Stable Election Protocol(SEP)techniques.It is observed that the proposed ILDA based IDHC approach provides better results with respect to Throughput,network residual energy,network lifetime and first node death round.
基金The work was financially supported by the National Natural Science Foundation of China (Nos. 51203182 and 51173202), Open Research Fund Program of the State Key Laboratory of Low-Dimensional Quantum Physics (No. KF201312), Key Laboratory of High Performance Fibers & Products, Ministry of Education, Donghua University, Guangxi Key Laboratory of Information Materials (Guilin University of Electronic Technology) (No. 1210908-01-K), Research Project of NUDT (No. JC13-01-05), Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province, and Aid Program for Innovative Group of National University of Defense Technology.
文摘The strategy of combining highly conductive frameworks with abundant active sites is desirable in the preparation of alternative catalysts to commercial Pt/C for the oxygen reduction reaction (ORR). In this study, N-doped graphene (NG) and carbon nanotubes (CNT) were grown in-situ on Co-containing carbon nanofibers (CNF) to form three-dimensional (3D) interconnected networks. The NG and CNT bound the interlaced CNF together, facilitating electron transfer and providing additional active sites. The 3D interconnected fiber networks exhibited excellent ORR catalytic behavior with an onset potential of 0.924 V (vs. reversible hydrogen electrode) and a higher current density than Pt/C beyond 0.720 V. In addition, the hybrid system exhibited superior stability and methanol tolerance to Pt/C in alkaline media. This method can be extended to the design of other 3D interconnected network architectures for energy storage and conversion applications.
文摘Background: The treatment of high-grade developmental spondylolisthesis (HGDS) is still challenging and controversial. In this study, we investigated the efficacy of the posterior reduction and monosegmental fusion assisted by intraoperative three-dimensional (3D) navigation system in managing the HGDS. Methods: Thirteen consecutive HGDS patients were treated with posterior decompression, reduction and monosegmental fusion ofL5/S1, assisted by intraoperative 3D navigation system. The clinical and radiographic outcomes were evaluated, with a minimum follow-up of 2 years. The differences between the pre- and post-operative measures were statistically analyzed using a two-tailed, paired t-test. Results: At most recent follow-up, 12 patients were pain-free. Only l patient had moderate pain, There were no permanent neurological complications or pseudarthrosis. The magnetic resonance imaging showed that there was no obvious disc degeneration in the adjacent segment. All radiographic parameters were improved. Mean slippage improved from 63.2% before surgery to 12.2% after surgery and 11.0% at latest follow-up. Lumbar lordosis changed from preoperative 34.9 ± 13.3° to postoperative 50.4 ±9.9°, and 49.3 ± 7.8° at last follow-up. L5 incidence improved from 71.0 ± 11.3° to 54.0 ± 1 1.9° and did not change significantly at the last follow-up 53.±1 15.4°. While pelvic incidence remained unchanged, sacral slip significantly decreased from preoperative 32.7± 12.5° to postoperative 42.6 ± 9.8°and remained constant to the last follow-up 44.4 ± 6.9°. Pelvic tilt significantly decreased from 38.4±12.5° to 30.9± 8.1° and remained unchanged at the last fbllow-up 28.1± 11.2°. Conclusions: Posterior reduction and monosegmental fusion of L5/S1 assisted by intraoperative 3D navigation are an effective technique for managing high-grade dysplastic spondylolisthesis. A complete reduction of local deformity and excellent correction of overall sagittal balance can be achieved.
文摘Purpose:This meta-analysis compared the clinical outcome of three-dimensional(3D)printing combined with open reduction and internal fixation(ORIF)to traditional ORIF in the treatment of acetabular fractures.Methods:We searched the Cochrane Library,PubMed,Embase,VIP database,CNKI,and Wanfang data-base with keywords"acetabular fracture","3D printing","three-dimensional printing","open reduction and internal fixation","Acetabulum","Acetabula"from January 2000 to March 2020.Two reviewers independently selected articles,extracted data,assessed the quality evidence and risk bias of included trials using the Cochrane Collaboration’s tools and/or Newcastle-Ottawa scale.When the two analysts had different opinions,they would ask the third analyst for opinion.Randomized controlled trials or retrospective comparative studies of 3D printing combined with ORIF(3D printing group)versus traditional ORIF(conventional group)in the treatment of acetabular fractures were selected.The data of operation time,intraoperative blood loss,intraoperative fluoroscopy times,incidence of complications,excellent and good rate of Matta score for reduction,and excellent and good rate of hip function score were extracted.Stata14.0 statistical software was used for data analysis.Results:Altogether 9 articles were selected,including 5 randomized controlled trials and 4 retrospective studies.A total of 467 patients were analyzed,250 in the conventional group,and 217 in the 3D printing group.The operation time in the 3D printing group was less than that in the conventional group and the difference was statistically significant(standardized mean difference(SMD)=-1.19,95%CI:-1.55 to-0.82,p<0.05).The intraoperative bleeding volume of the 3D printing group was significantly lower than that of the conventional group(SMD=-1.08,95%CI:-1.65 to-0.51,p<0.05).The fluoroscopy times were less in the 3D printing group than in the conventional group and the difference was statistically significant(SMD=-1.64,95%CI:-2.35 to-0.93,p<0.05).The total incidence of complications in the 3D printing group was significantly lower than that in the conventional group(OR=0.43,95%CI:0.24-0.79,p<0.05).There was no significant difference in the excellent and good rate of Matta score for reduction between the two groups(OR=0.60,95%CI:0.34-1.06,p>0.05).There was no significant difference in the excellent and good rate of hip function score at the end of postoperative follow-up between the two groups(OR=0.84,95%CI:0.46-1.56,p>0.05),but the follow-up time varies from 6 months to 40 months.Conclusion:Compared with traditional ORIF,3D printing combined with ORIF has certain advantages in terms that 3D printing not only helps surgeons to understand acetabular fractures more intuitively,but also effectively reduces operation time,intraoperative blood loss,intraoperative fluoroscopy times,and postoperative complications.However,there were no significant differences in the excellent and good rate of Matta score for reduction and the excellent and good rate of hip function score at the end of follow-up.
文摘Holograms provide a characteristic manner to display and convey information, and have been improved to provide better user interactions Holographic interactions are important as they improve user interactions with virtual objects. Gesture interaction is a recent research topic, as it allows users to use their bare hands to directly interact with the hologram. However, it remains unclear whether real hand gestures are well suited for hologram applications. Therefore, we discuss the development process and implementation of three-dimensional object manipulation using natural hand gestures in a hologram. We describe the design and development process for hologram applications and its integration with real hand gesture interactions as initial findings. Experimental results from Nasa TLX form are discussed. Based on the findings, we actualize the user interactions in the hologram.
文摘目的:通过Meta分析,比较手法复位联合咬合板治疗颞下颌关节盘不可复性前移位患者疼痛与最大张口度疗效是否优于仅进行手法或仅进行咬合板治疗。方法:计算机检索Web of Science、PubMed、Cochrane Library、维普(VIP)、中国知网(CNKI)、万方中手法复位联合咬合板治疗颞下颌关节盘不可复性前移位的随机对照试验(RCTs)文献,并参考Cochrane手册评估文献质量,运用RevMan5.4软件分析结局指标。结果:本研究纳入6个RCTs,患者共计393例。Meta分析结果显示,对于颞下颌关节盘不可复性前移位患者,观察组进行手法复位联合咬合板治疗,在降低疼痛评分[SMD=-0.34,95%CI(-0.54,-0.13),P=0.001]与改善最大张口度[SMD=0.51,95%CI(0.31,0.71),P<0.00001]方面疗效均比对照组较优,差异具有统计学意义(P<0.05)。结论:手法复位联合咬合板治疗改善颞下颌关节盘不可复性前移位患者疼痛和最大张口度疗效优于单独使用手法复位或单独佩戴咬合板。